Usually, what this means is Single Ladies Brunch. (There's also Single Bros Brunch, and Single Gays Brunch, but the former is rare, and the latter is too complex for a straight guy to discuss in responsible detail.) Single Ladies Brunch is different than "Cute" Brunch in several ways: everyone is single, everyone is a lady, and everyone is either going to Coachella, just got back from Coachella, or already bought their tickets for next year's Coachella. 'CHELLA #VIBES, BETCH!
Single Ladies Brunch will often involve shots, gossip, aviator sunglasses, and someone named Taylor showing up late because she was at Pure Barre. It is loud, it is chaotic, and it is fundamentally uncontrollable. There's no telling whether Single Ladies Brunch will end in tears, a dive bar, or tears cried in a dive bar. Fear Single Ladies Brunch.